We present three important types of posttraumatic deformity of the distal humerus: varus deformity, valgus deformity and complex deformity. Their primary causes are discussed. Slight varus deformities are the result of purely lateral slip of supracondylar fractures or radial overgrowth after a lateral condylar fracture. Severe varus deformities occur after ulnar slip of the distal fragment following supracondylar fracture caused by a rotational deformity. The results after correlation of varus deformities with a rotational deformity are poor. The only way of obviating this problem is to recognize a rotational deformity as soon as possible before adaptation of the elbow occurs, and also to correct it early, if necessary. Valgus deformities occur mostly after radial malunion. Depending on the size of the fragment and the disability of the patient, the fragment should be stabilized-but the potential involvement of the malunion in the elbow function must be borne in mind. Complex deformities and their unknown origins are also discussed. The correction of such deformities depends exclusively on the elbow function. More aggressive primary regimens are urgently needed to prevent the necessity for such secondary corrections, which are very demanding and, depending on the type, have a high failure rate.